Question

Find the mean of 25 numbers, if the mean of 15 of them is 18 and the mean of remaining numbers is 13. A) 26 B) 44 C) 39 D) 16

Answer 1

Option D)

Given :-

Mean of 15 of them is 18 and mean of remaining is 13.

To Find :-

Mean of 25 numbers.

Solution :-

Mean of 15 of them is 18.

Sum of 15 numbers = 15x18 = 270.

Mean of remaining numbers is 13.

Remaining numbers = 25 - 15 = 10.

Sum of 10 numbers = 13 * 10 = 130.

Total = 270 + 130 = 400.

Mean of 25 numbers = 400/25 = 16.

Result :-

Mean of 25 numbers is 16.

Answer 2

Step-by-step explanation:

Since we have given that

Mean of 15 numbers = 18

Mean of 10 numbers = 13

We need to find the mean of 25 numbers.

So, Mean of 25 numbers would be

$</p><p> \sf \: \begin{lgathered}\dfrac{15\times 18+10\times 13}{25}\\\\ \sf \: =\dfrac{400}{25}\\\\ \sf=16\end{lgathered}$

Hence, Option 'd' is correct